Why Is the Battle Over the Hetch Hetchy Dam Significant

Why is the battle over the Hetch Hetchy dam significant in the history of U.S. environmentalism?

A) It was the pivotal event in the contest between preservationists and conservationists.
B) It was the first time the government set aside public lands for conservation.
C) It was the first environmental issue to capture the attention of President Theodore Roosevelt.
D) It was the first time everyday citizens had organized to resist environmental degradation.